Cambodian police are investigating the death of another opposition party activist in the run-up to the July 27 general elections.

Authorities say the 50-year-old activist, Proeng Norn, was shot to death Sunday night at his home in northern Kampong Thom province. He was a member of the royalist Funcinpec party.

More than 15 people, mostly opposition supporters, have been killed this year in violence that is considered election related. Election monitors say they fear that pre-election violence in Cambodia could spiral and ruin the voting.

The ruling Cambodian People's party is the front-runner in the polls. It denies opposition charges that it is encouraging violence in an attempt to intimidate and harass its critics.